A high-performance, mobile-first platform that helped millions of UK voters find their political match — and was trusted by The Telegraph to power their election coverage.
Project led by Nick Tatt, Founder & Technical Director
The Brief
VoteMatch is a voter advice application owned by Unlock Democracy, designed to increase democratic participation by matching users with political parties based on their policy preferences. For the 2015 UK General Election, Tinderhouse was commissioned to completely rebuild the platform to meet the demands of a mobile-first electorate - and the traffic requirements of a national election.
The previous version had reached 1.25 million users during the 2010 election. The target for 2015 was ambitious: 3–5 million users, with the infrastructure to handle peak loads during televised debates and polling day itself.
Beyond the public-facing quiz, the project served as a data hub for major media partners. The platform was officially backed by the London School of Economics and the Oxford Internet Institute, and white-labelled for embedding on Telegraph Media Group's website - meaning our infrastructure would be serving national newspaper audiences on election night.
Failure wasn't an option.
The Challenge
The technical requirements reflected the stakes:
Extreme traffic peaks: The system needed to handle 100,000+ concurrent users during peak moments: televised debates, viral social sharing, and the final 48 hours before polls opened.
Zero-downtime requirement: With The Telegraph embedding the tool for their election coverage, any outage would be visible to millions and damage both their reputation and ours.
Platform fragmentation: The app needed to work seamlessly across Android 2.3+, iOS 6+, and all modern desktop browsers. No voter could be excluded due to their device.
Real-time content updates: Party positions could shift during the campaign. The editorial team needed to update policy statements instantly, without developer intervention.
White-label architecture: Media partners, like The Telegraph, required their own branded versions, deployable under custom subdomains, while all data fed back to a central repository for analysis.
Offline resilience: In areas with poor mobile signal (rural polling stations, underground transport), the app needed to remain functional.
Our Approach
Mobile-First MVP Development
We began with a minimum viable product strategy, ensuring the core matching engine was bulletproof before layering on secondary features. This allowed us to test the interface across a wide range of handsets early in the development cycle, refining the swipe mechanics and postcode lookup to minimise friction between splash screen and results.
High-Availability Infrastructure
To handle the traffic surge, we designed a custom server environment behind a load balancer that allowed horizontal scaling across multiple nodes. We implemented Redis caching, App Cache manifests, and WebStorage for offline capabilities - meaning once the app loaded, much of the logic remained available even if connectivity dropped.
The architecture was stress-tested against projected peak loads before launch. On election night, it handled everything we threw at it.
ExpressionEngine as a Data Hub
As ExpressionEngine specialists, we configured the CMS as a bespoke data management system - not a standard website build. It managed thousands of data points: party statements across multiple policy areas, candidate lists by constituency, geographic variations for England, Scotland, Wales, and Northern Ireland, and real-time user results.
This gave Unlock Democracy's editorial team the agility to respond to campaign developments without touching code.
Geolocation and Personalisation
We integrated postcode-to-constituency lookups so users saw candidates and parties specific to their local area. This transformed the app from a generic quiz into a tool for local democratic engagement - a hallmark of our public sector development work.
Social Propagation and White-Labelling
To hit the 5 million target, the app needed to be inherently viral. We integrated Twitter Cards and Facebook Open Graph to enable one-tap sharing of results. The white-label architecture allowed partners including The Telegraph and The Independent to host the VoteMatch engine within their own ecosystems, driving traffic through high-authority media channels.
Academic analysis of the 2015 election confirmed these "formal partnerships between VoteMatch and Verto with the Telegraph, Huffington Post and Independent."
The Results
100,000+ concurrent users handled at peak load with no degradation in performance or availability.
Millions of voters reached across the platform and white-label partner sites, meeting the project's ambitious targets.
Measurable democratic impact - Analysis by politics.co.uk found that 13% of users changed their vote based on their results, and 4.5% (over 100,000 people) voted specifically as a direct consequence of using the app.
Trusted by national media - The Telegraph embedded VoteMatch for their election coverage, relying on our infrastructure for a national audience on polling day.
Adopted as authoritative source - 38 Degrees, with over 2 million members, used VoteMatch as their official source for party policy positions.
Technical Summary
- CMS: ExpressionEngine (enterprise configuration)
- Stack: LAMP/LEMP with NginxCachingRedis, App
- Cache: Manifest, WebStorage
- Frontend: HTML5, CSS3, JavaScript (mobile-first responsive)
- APIs: Secure REST API (XML/JSON), postcode-constituency lookup
- Social: Facebook Open Graph, Twitter Cards
- Security: SSL/TLS encryption on all data collection
What This Project Taught Us
Building for a national election is unlike any other brief. The deadline is immovable, the stakes are public, and the traffic is unpredictable. Three lessons we took forward:
- Stress-test against 2x your projected peak - Viral moments don't announce themselves. We built headroom into the infrastructure that saved us during unexpected spikes.
- White-label from the start - Retrofitting multi-tenant architecture is painful. We designed for it from day one, which made the Telegraph and Independent integrations straightforward.
- Give editors real control - In a fast-moving campaign, developers become a bottleneck. The ExpressionEngine configuration let the editorial team own their content completely.
Further Reading
We documented our technical insights from the VoteMatch project at the time:
- The Ebb and Flow of a Mobile-First Website - How we validated our mobile-first approach through real-time analytics, tracking device usage patterns throughout the day and the viral mechanics of in-app social sharing.
- Make It Easy to Share the Love - The technical challenge of building embeddable white-label versions that returned social traffic to partner sites rather than cannibalising their audience.
Build Something That Scales
Whether you're launching a high-traffic platform, a civic technology tool, or an application that needs to handle unpredictable demand, we've done it before - under pressure, with national visibility, and zero margin for error.
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