Construction is one of the last industries where "real-time" still means calling someone on a radio. Fintech has sub-millisecond trading. Logistics has live GPS tracking across entire fleets. Healthcare has real-time patient monitoring dashboards. But most construction software? Manual refresh. Daily syncs. "Check back tomorrow."
That gap is closing fast. Real-time collaboration features -- live bid tracking, instant RFI notifications, simultaneous plan markup, real-time workforce availability -- are becoming the differentiator between construction platforms that win adoption and those that gather dust on an iPad in a job trailer.
If you are building or evaluating real-time construction software, the architecture decisions you make early will determine whether your platform can handle bid day chaos, unreliable field connectivity, and thousands of concurrent users. This guide covers the real-time architecture options, the tech stacks that work best for construction, and the practical considerations that most teams discover too late.
Where Real-Time Matters in Construction
Not every feature in a construction platform needs real-time updates. Some data is fine refreshing every few minutes. But there are specific workflows where even a five-minute delay creates real problems.
Bid Day Coordination
Bid day is the highest-stakes moment in preconstruction. Multiple estimators track incoming subcontractor bids, monitor scope coverage gaps, and update pricing -- all simultaneously, all against a hard deadline. When a sub's number comes in $200K under the next closest bid, every estimator on the team needs to see it immediately. Every minute of delay on bid day costs money, and stale data leads to coverage gaps that blow up a general contractor's margin.
Real-time construction software for bid management needs live-updating bid boards, instant notifications when new bids arrive, and the ability for multiple users to work in the same scope sheet without overwriting each other's changes.
RFI and Submittal Tracking
When an RFI response arrives from the architect, the entire project team needs visibility immediately -- the project manager, superintendent, and affected subcontractors. Waiting for the next daily sync or a manual email forward means the field crew keeps working with outdated information. On a fast-track project, that delay can mean rework.
Real-time RFI tracking means the response shows up on every stakeholder's dashboard the moment it is logged. No refresh button. No "did you see the email?"
Workforce Scheduling and Dispatch
Construction workforce scheduling is a coordination problem that changes by the hour. A worker calls in sick. A concrete pour gets pushed back due to weather. A project accelerates and needs additional hands tomorrow morning. When any of these events happen, the availability board needs to update instantly across all dispatchers and project managers.
Polling-based systems that refresh every 30 seconds create a window where two dispatchers can double-book the same crew. Real-time presence and locking solve this.
Safety Incident Reporting
When a safety incident occurs on a job site, the report needs to reach safety managers, project managers, and executives in seconds -- not hours. Delayed incident reports create liability exposure and prevent rapid response. Real-time notification systems ensure the right people know about incidents the moment they are reported from the field.
Daily Log Collaboration
Daily reports involve input from superintendents, foremen, project managers, and sometimes owners. When multiple people contribute to the same daily log simultaneously -- weather conditions, manpower counts, equipment usage, work performed -- they need to see each other's entries in real-time to avoid duplication and ensure completeness.
Plan Markup and Redlines
Architects and engineers reviewing and marking up plans together in real-time eliminates the painful cycle of emailing PDFs back and forth, waiting for consolidated comments, and reconciling conflicting markups. Live cursors, real-time drawing tools, and simultaneous annotation reduce review cycles from days to hours.
Equipment Tracking
GPS and utilization data from equipment sensors -- engine hours, idle time, fuel consumption, location -- need to stream to dashboards in near real-time. When a piece of equipment moves off-site without authorization or a machine's utilization drops to zero mid-shift, project managers need to know immediately.
Real-Time Architecture Options for Construction Platforms
There is no single "right" architecture for real-time construction software. The correct choice depends on the specific use case, the scale you need to support, and the development resources available. Here are the primary approaches, with honest trade-offs.
HTTP Polling
The simplest approach: the client asks the server "anything new?" every N seconds.
How it works: A JavaScript setInterval fires an HTTP request every 10, 30, or 60 seconds. The server responds with any updates since the last request.
Pros:
- Trivial to implement on top of any existing REST API
- Works through every proxy, firewall, and CDN
- No special infrastructure required
Cons:
- Latency equals the polling interval -- a 30-second poll means up to 30 seconds of stale data
- Wasteful of bandwidth; most responses return "no updates"
- Scales poorly; 1,000 users polling every 10 seconds means 100 requests per second even when nothing has changed
Best for: Dashboard metrics refreshing every 30-60 seconds, progress tracking that does not require instant updates.
Not suitable for: Bid day coordination, simultaneous editing, or any workflow where five seconds of latency causes problems.
Server-Sent Events (SSE)
A one-way push channel from server to client over a standard HTTP connection.
How it works: The client opens a long-lived HTTP connection. The server pushes events down that connection whenever updates are available. The connection stays open until the client closes it or the server terminates it.
Pros:
- Simple to implement -- it is just HTTP with a
text/event-streamcontent type - Built-in browser reconnection with
EventSourceAPI - Works through most proxies and load balancers
- More efficient than polling -- the server only sends data when there is something to send
Cons:
- One-way only; the client cannot send messages back through the SSE connection
- Limited to text-based data (no binary)
- Some older enterprise proxies buffer SSE responses, adding latency
Best for: Notification feeds, RFI status updates, safety alerts, live activity logs, equipment tracking dashboards. Anywhere the server pushes updates and the client just listens.
Not suitable for: Collaborative editing, live chat, or any feature where the client needs to send real-time messages to the server.
WebSockets
Full-duplex bidirectional communication over a single persistent TCP connection.
How it works: The client initiates a standard HTTP request with an Upgrade header. If the server accepts, the connection upgrades to the WebSocket protocol. Both sides can then send messages at any time without the overhead of HTTP headers on each message.
Pros:
- True bidirectional communication -- required for collaborative editing, live cursors, and chat
- Low latency; messages arrive in milliseconds
- Efficient; no HTTP header overhead per message
Cons:
- More complex to implement than SSE or polling
- Connection management is non-trivial: reconnection logic, heartbeats, state synchronization on reconnect
- Load balancing requires sticky sessions or a distributed PubSub layer
- Some corporate firewalls and older proxies do not support WebSockets
Best for: Simultaneous plan markup, bid day live boards, collaborative daily logs, real-time chat, presence indicators ("John is viewing this RFI").
Phoenix LiveView (Elixir)
Server-rendered real-time UI over WebSockets, with no JavaScript framework required on the client.
How it works: The initial page load delivers server-rendered HTML. A WebSocket connection is established, and subsequent interactions (clicks, form submissions, server-side updates) are handled by sending minimal DOM diffs over that connection. The server maintains the UI state.
Pros:
- Dramatically reduces frontend complexity -- no React, no state management library, no REST API to maintain
- Sub-50ms updates for most interactions
- Built-in presence tracking, PubSub, and connection recovery
- A single Phoenix server can handle 2 million+ concurrent WebSocket connections
Cons:
- Requires Elixir expertise (smaller talent pool than JavaScript or Python)
- Server maintains state for every connected client, which increases memory usage per connection
- Less suitable for highly interactive client-side UIs (drag-and-drop plan markup may still need JavaScript)
Best for: Live dashboards, real-time tables and lists, bid boards, workforce availability views, RFI tracking, and administrative interfaces. This is our preferred approach for many construction use cases because it delivers excellent real-time performance while cutting frontend development time in half.
WebRTC
Peer-to-peer data channels, primarily designed for audio and video streaming.
How it works: After an initial signaling phase (typically via WebSockets), clients establish direct peer-to-peer connections for data transfer.
Pros:
- Lowest possible latency for peer-to-peer communication
- Excellent for video calling and screen sharing
Cons:
- Complex signaling and NAT traversal setup
- Overkill for most construction collaboration features
- Peer-to-peer architecture does not scale well for many-to-many communication
Best for: Video conferencing features within construction platforms, remote site inspections via live video.
Not suitable for: General real-time data synchronization, notifications, or collaborative editing.
Recommended Tech Stack for Real-Time Construction Apps
After building real-time applications across multiple industries, we have landed on a stack that handles the specific demands of construction software particularly well.
Backend: Elixir and Phoenix
Elixir, running on the Erlang BEAM virtual machine, was designed from the ground up for real-time, concurrent, fault-tolerant systems. This is not marketing language -- it is literally what the BEAM was built for. Ericsson created it to run telephone switches that needed to handle millions of simultaneous connections with zero downtime.
Why Elixir for construction specifically:
- Bid day concurrency: Construction apps need to handle hundreds of concurrent users all hitting the same bid board simultaneously. Each connection in Elixir is a lightweight process (not an OS thread), and the BEAM can manage millions of these processes on a single machine. A single Phoenix server handles 2M+ concurrent WebSocket connections.
- Equipment data ingestion: Thousands of data points streaming from equipment sensors require efficient message processing. Elixir's actor model processes each message independently without blocking.
- Unreliable networks: When field workers on spotty cellular connections drop and reconnect repeatedly, OTP supervision trees automatically restart failed processes. The system self-heals without manual intervention.
- Built-in PubSub: Phoenix PubSub is included in the framework. Broadcasting an update to every user watching a specific bid takes one line of code, not a separate message broker.
Alternative Backend: Node.js with Socket.io
Node.js with Socket.io is a viable alternative, especially if your team already has deep JavaScript expertise.
Advantages: Larger ecosystem of libraries and tools. More developers available for hire. Extensive community support and documentation.
Trade-offs: Node.js runs on a single-threaded event loop, which means CPU-intensive operations (PDF generation, complex calculations) can block real-time message delivery. Scaling to thousands of concurrent WebSocket connections requires more infrastructure (Redis adapter, multiple Node processes, sticky sessions) compared to Elixir where this works out of the box.
For a construction platform that needs to handle bid day peaks of 500+ concurrent users, we have found Elixir requires roughly 1/3 the infrastructure cost of an equivalent Node.js deployment.
Database: PostgreSQL
PostgreSQL is the backbone for most construction platforms, and it has a feature that pairs exceptionally well with real-time systems: LISTEN/NOTIFY.
When a row is inserted or updated in the database, PostgreSQL can send a notification on a named channel. Your Elixir or Node.js backend listens on that channel and broadcasts the update to connected clients. This means your real-time notifications are triggered at the database level -- even if an update comes from a background job, a migration script, or a direct SQL query, connected clients still see the change immediately.
For multi-node deployments where you need cross-server message delivery, add Redis PubSub as a transport layer. Phoenix has built-in Redis PubSub adapters. Socket.io has the same.
Frontend: Phoenix LiveView or React
For dashboards, live tables, bid boards, and administrative interfaces, Phoenix LiveView eliminates the need for a separate frontend framework entirely. Your team writes Elixir, and the framework handles rendering, diffing, and updating the DOM over WebSockets.
For features that demand heavy client-side interactivity -- drag-and-drop plan markup, complex drawing tools, offline-first mobile interfaces -- React with a WebSocket client library is the better choice. The two approaches can coexist in the same application.
Mobile: React Native or Progressive Web App
Field workers need access from phones and tablets on job sites. Two viable approaches:
- React Native with a WebSocket client provides native performance and access to device features (camera for photo documentation, GPS for location tracking).
- Progressive Web App (PWA) eliminates app store deployment friction. Workers open a URL and get a near-native experience. Service workers enable offline functionality.
The right choice depends on whether you need native device APIs (camera, Bluetooth for sensor integration, push notifications on iOS) or whether browser capabilities are sufficient.
Handling Unreliable Connectivity: The Construction-Specific Challenge
This is where most real-time architecture guides stop being useful for construction. They assume reliable broadband connections. Construction job sites have a different reality:
- Cellular coverage is spotty or nonexistent on remote sites
- Site wifi, when it exists, is shared by 50+ devices and drops regularly
- Workers move between areas with and without coverage throughout the day
- Underground work, steel structures, and concrete buildings block signals
If your real-time construction software falls apart when the connection drops, nobody on the job site will use it. Offline-first architecture is not optional -- it is a core requirement.
Offline-First Data Architecture
The principle is simple: the app works without a connection and syncs when connectivity returns. The implementation is complex.
Local data storage: Use IndexedDB (browser) or SQLite (React Native) to store a local copy of the data the user needs. When the user creates a daily log entry, it writes locally first and queues the mutation for server sync.
Mutation queue: All write operations are queued locally with timestamps. When connectivity returns, the queue is flushed to the server in order. The UI shows the user their own changes immediately (optimistic UI) without waiting for server confirmation.
Sync engine: On reconnect, the client sends its queued mutations and receives any updates it missed. This requires the server to track what each client has seen -- typically via sequence numbers or vector clocks.
Conflict Resolution
When two users edit the same record while one or both are offline, you need a conflict resolution strategy.
Last-write-wins (LWW): The most recent timestamp wins. Simple to implement, but loses data. Acceptable for status updates and simple field edits where the latest value is inherently correct.
Operational Transforms (OT): Transforms concurrent edits so both can be applied. Used by Google Docs. Complex to implement but preserves all changes. Appropriate for collaborative text editing (daily logs, RFI responses).
CRDTs (Conflict-free Replicated Data Types): Data structures that can be merged automatically without conflicts. Excellent for counters (manpower counts), sets (tag lists), and registers (field values). More complex to implement than LWW but simpler than OT for specific data types.
For most construction use cases, we recommend a hybrid approach: LWW for simple field updates, CRDTs for counters and sets, and manual conflict resolution UI for complex cases where the system cannot determine the correct merge automatically.
Reconnection Strategies
When a WebSocket connection drops (and on construction sites, it will), the client needs to reconnect gracefully.
Exponential backoff: First retry after 1 second, then 2, then 4, then 8, up to a maximum interval. This prevents thundering herd problems when a site's wifi comes back online and 200 devices try to reconnect simultaneously.
State catchup on reconnect: When the connection reestablishes, the client sends its last known sequence number. The server responds with all events since that point. The client applies them in order.
Degradation indicators: Show users clear status indicators. "Connected -- live updates," "Reconnecting...," or "Offline -- changes will sync when connected." Do not hide connection state from users. Field workers understand connectivity is unreliable; they just need to know whether what they are looking at is current.
Progressive Enhancement
Design the app to be fully functional without real-time features, then layer real-time on top.
The daily log form should work as a standard form submission. If WebSockets are connected, other users see the entry appear instantly. If not, it syncs on the next page load. Real-time is the enhancement, not the foundation. This approach ensures the app is usable even on the worst connections.
Scaling Real-Time Construction Systems
Real-time systems have different scaling characteristics than traditional request-response applications. Here is what you need to plan for.
Connection Management
Every WebSocket connection is a persistent TCP connection. Unlike HTTP, where a connection is opened, a response is sent, and the connection is closed, WebSocket connections stay open for the duration of the user's session.
10,000 concurrent users means 10,000 open connections. Each connection consumes memory on the server for its state (what topics the user is subscribed to, their authentication context, buffered messages).
On Elixir/Phoenix, each connection is a lightweight BEAM process consuming roughly 2-5 KB of memory. 10,000 connections use approximately 20-50 MB of RAM. On Node.js, each connection has a higher memory overhead, and you will need to distribute across multiple processes sooner.
Horizontal Scaling
When a single server is not enough, you need multiple nodes communicating with each other.
The problem: User A is connected to Server 1 and updates a bid. User B is connected to Server 2 and needs to see that update. The servers need a way to relay messages between them.
Solutions:
- Redis PubSub: Both servers subscribe to Redis. When Server 1 receives an update, it publishes to Redis. Server 2 receives the message from Redis and pushes it to User B. Adds 1-3ms latency.
- Elixir distributed PubSub: Elixir nodes connect directly to each other via the BEAM's built-in distribution protocol. No external message broker required. Sub-millisecond cross-node messaging.
Topic-Based Subscriptions
Not every user needs every update. When a bid update happens on Project #4527, only users who are actively watching that project need to be notified.
Structure your PubSub topics hierarchically:
project:4527:bids-- bid updates for a specific projectproject:4527:rfis-- RFI updatescompany:acme:safety-- safety alerts across all of a company's projectsuser:jane:notifications-- personal notification channel
When a user opens a bid board, subscribe them to project:4527:bids. When they navigate away, unsubscribe. This prevents wasting bandwidth and server resources on updates nobody is watching.
Presence Tracking
Presence answers the question: "Who else is looking at this right now?"
Phoenix has a built-in Presence module that tracks which users are connected, what they are viewing, and when they were last active. This powers features like:
- "3 people are viewing this bid board" indicators
- Live cursors during plan markup
- "Jane is editing this RFI response" locking
- Active user lists in daily logs
Building equivalent presence tracking in Node.js requires additional infrastructure (Redis, a custom presence server, or a third-party service like Pusher).
Rate Limiting
Bid day creates message storms. When 50 subcontractor bids arrive in 10 minutes and 20 estimators are watching the board, that is 50 x 20 = 1,000 messages in a short window. Add scope change notifications, chat messages, and status updates, and you can hit thousands of messages per second.
Rate limiting strategies:
- Debounce updates: If a bid amount changes 5 times in 3 seconds (estimator adjusting numbers), send only the final value
- Batch updates: Collect changes over a 100ms window and send them as a single message
- Priority queues: Safety alerts get immediate delivery; dashboard metrics can wait
Implementation Cost and Timeline
These ranges are based on our experience building real-time applications. Your specific costs will vary based on feature complexity, scale requirements, and team composition.
Adding Real-Time to an Existing Construction App
Typical range: $20,000 - $60,000 over 2-4 months
This assumes you have an existing web application and want to add specific real-time features. Examples:
- Live-updating bid board: $15K-25K
- Real-time notification system: $10K-20K
- Collaborative daily log editing: $20K-35K
- Presence indicators ("who's online"): $5K-10K
Cost depends heavily on the existing architecture. If the backend is already in Elixir or Node.js, adding WebSockets is straightforward. If it is a traditional server-rendered application (Rails, Django, .NET), you may need to introduce a separate real-time service.
Building a Real-Time-First Construction Platform
Typical range: $100,000 - $250,000 over 5-10 months
This is a ground-up build where real-time is a core architectural requirement, not a bolt-on feature. Includes:
- Real-time architecture design and infrastructure
- Core application features (project management, bid tracking, scheduling)
- Offline-first mobile support
- Authentication, authorization, and role-based access
- Integration with existing tools (email, accounting, ERP)
Key Cost Drivers
- Number of real-time features: Each collaborative feature (editing, presence, notifications) adds development complexity
- Offline support: Offline-first with conflict resolution can double the frontend development effort compared to online-only
- Mobile apps: Native mobile apps add $30K-80K on top of web. PWAs are significantly cheaper.
- Scale requirements: Supporting 100 concurrent users is fundamentally different from supporting 10,000
- Compliance: If your platform handles sensitive data (worker PII, financial bid data), security requirements add 15-25% to development costs
Ongoing Infrastructure Costs
WebSocket-based infrastructure typically costs $200-800/month more than equivalent HTTP-only hosting. The additional cost comes from:
- Persistent connections consuming more memory per server
- PubSub infrastructure (Redis or equivalent)
- Higher bandwidth from real-time message delivery
- Connection-aware load balancers
For most construction platforms, total hosting runs $500-2,000/month depending on user volume and data throughput.
Choosing the Right Architecture for Your Platform
Not every construction platform needs the same real-time architecture. Here is a decision framework.
Start with SSE if: You primarily need server-to-client push (notifications, status updates, live dashboards) and your users are consuming data rather than collaborating on it.
Use WebSockets if: You need bidirectional communication -- collaborative editing, real-time chat, live presence indicators, or any feature where clients send messages to each other through the server.
Use Phoenix LiveView if: You want the fastest path to a real-time UI without the complexity of maintaining separate frontend and backend codebases. Ideal for internal tools, dashboards, and administrative interfaces.
Use polling if: Real-time latency under 30 seconds is not critical, you need the simplest possible implementation, or you are adding lightweight refresh to an existing legacy system.
The best approach is often a hybrid. Use LiveView for dashboards and admin interfaces, WebSockets for collaborative features, SSE for mobile notification feeds, and polling as a fallback for legacy integrations.
Frequently Asked Questions
What is real-time collaboration in construction software?
Real-time collaboration in construction software means multiple users can view and interact with the same data simultaneously, with changes appearing instantly across all connected devices. This includes features like live bid tracking where estimators see new subcontractor bids the moment they arrive, collaborative daily logs where multiple superintendents contribute to the same report at the same time, and instant RFI notifications that reach the entire project team in seconds rather than waiting for email. Unlike traditional construction software that requires manual refresh or scheduled syncs, real-time systems push updates to users automatically over persistent connections.
Why use Elixir and Phoenix for construction applications?
Elixir runs on the Erlang BEAM virtual machine, which was purpose-built for handling massive numbers of simultaneous connections with fault tolerance -- originally for telephone switches. This makes it ideal for construction software where hundreds of users may be connected during bid day, thousands of equipment data points stream in continuously, and field workers on unreliable cellular connections drop and reconnect frequently. A single Phoenix server handles over 2 million concurrent WebSocket connections. Phoenix includes built-in PubSub for broadcasting updates, a Presence module for tracking who is online, and LiveView for building real-time UIs without a separate frontend framework. The result is less infrastructure, less code, and better real-time performance compared to alternatives like Node.js for high-concurrency workloads.
How much does real-time construction software cost to build?
Adding real-time features to an existing construction application typically costs $20,000-$60,000 and takes 2-4 months, depending on the number of features and the existing architecture. Building a real-time-first construction platform from the ground up ranges from $100,000-$250,000 over 5-10 months, including core application features, offline-first mobile support, and integration with existing tools. Key cost drivers include the number of collaborative features, offline support complexity (which can double frontend development effort), mobile app requirements, and scale. Ongoing infrastructure costs for WebSocket-based systems run $200-800/month more than traditional HTTP hosting due to persistent connections, PubSub infrastructure, and connection-aware load balancing.
Build Real-Time Construction Software That Works on the Job Site
The construction industry is moving past "check back tomorrow" software. Teams that adopt real-time collaboration -- live bid boards, instant notifications, collaborative documentation, real-time scheduling -- gain a measurable advantage in coordination speed, data accuracy, and field adoption.
The architecture decisions you make now determine whether your platform can handle the realities of construction: unreliable connectivity, bid day traffic spikes, and users who need their tools to work whether they have signal or not.
Of Ash and Fire specializes in real-time application architecture using Elixir/Phoenix and WebSocket technologies. We have built real-time systems that handle thousands of concurrent connections with sub-second update delivery, offline-first mobile support, and the fault tolerance that construction demands.
If you are building a construction platform that needs real-time collaboration, or evaluating how to add real-time features to an existing product, we would like to hear about it. We will help you choose the right architecture, avoid the pitfalls, and build something your users actually want to open on the job site.
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