Illuminate Investing — ESG Portfolio Tracker with Carbon Intensity Analytics Built in Flutter
The Vision
Illuminate was founded on a simple premise: retail investors care about climate impact but lack the tools to connect their investment decisions to real-world environmental outcomes. Existing investment apps show portfolio performance; none showed the carbon footprint of that performance.
The founder came to us with three core product requirements:
- Dual-axis performance tracking — financial returns and carbon intensity (kg CO₂e per $100 invested) on the same chart, updated in real time
- Curated ESG collections — themed investment bundles (Wind Power, Solar, EVs, Decarbonising Electricity) with verified carbon methodology, browsable by a general audience without finance expertise
- Climate intelligence feed — contextual news and research that connects market events to environmental outcomes, so investors understand why their portfolio's carbon intensity changes
What We Built
Portfolio Dashboard
The home screen surfaces the investor's current balance alongside a dual-line chart plotting financial return vs. carbon intensity over 1D / 1W / 1M / 3M / YTD / 1Y timeframes. The chart updates on a 15-minute polling cycle during market hours.
Below the chart, two "Portfolio Impact Highlight" cards surface the most significant ESG events affecting the portfolio that week — a company in the portfolio announcing a renewable energy target, a fund divesting from coal, or a sector-wide carbon reduction milestone.
Portfolio Breakdown
A detailed breakdown screen shows allocation across Projects (direct impact investments), Companies (public equities screened for ESG criteria), and Funds (ESG-themed ETFs and managed funds), with a donut chart visualising the split. Each allocation line links to the underlying holding's impact profile.
The portfolio detail view shows individual holding performance with its standalone carbon intensity, allowing investors to identify which holdings are pulling their overall CO₂e number up or down.
Discover — ESG Collection Browser
A searchable discovery screen lets users browse investment opportunities across four primary asset types: Projects, Collections, Stocks, Bonds, and Funds. Each collection card shows the asset's carbon methodology badge and average return.
Featured trending collections (Wind Power, Electric Vehicles, Decarbonising Electricity, Solar Power) are surfaced with brief impact descriptions — written for a climate-aware but non-finance-expert audience.
Climate Center Feed
A content feed surfaces weekly climate-finance briefings, company sustainability announcements, and policy updates — each tagged to the portfolio holdings they affect. The feed is curated by the Illuminate editorial team and published via the admin CMS.
Article pages are clean, long-form reader experiences: author attribution, publication date, full-resolution header images, and estimated read time. No ads, no pop-ups.
Tech Stack
| Layer | Technology |
|---|---|
| Mobile | Flutter 3 / Dart (iOS + Android) |
| State Management | Bloc / Cubit |
| Backend | Node.js + Express |
| Database | PostgreSQL |
| Market Data | Financial data API (real-time quotes) |
| Carbon Data | Custom carbon intensity scoring engine |
| Push Notifications | Firebase Cloud Messaging |
| Analytics | Firebase Analytics |
| Storage | AWS S3 (article media) |
| Admin CMS | React.js |
Results
4.6★ App Store rating at launch, with reviewers highlighting the dual financial/carbon chart as "unlike anything else in the investment app market."
$2.4M in assets under management tracked through the platform within 90 days of launch, from the initial beta cohort of 1,200 investors.
71% weekly active rate — investors return multiple times per week to check carbon intensity alongside portfolio performance, compared to the 35–45% WAU benchmark for personal finance apps.
Sub-400ms chart render time for 1-year historical data — achieved through pre-aggregated timeseries snapshots stored in PostgreSQL and served from a Redis cache layer.
14 ESG-verified collections available at launch, each with audited carbon methodology — the client's product differentiator against generic robo-advisor competitors.
Climate Center launch article on Paris Olympics sustainability reached 8,400 unique readers in the first week, demonstrating appetite for the climate-finance content layer beyond just portfolio tracking.
What Made This Work
The carbon intensity scoring was the hardest problem to get right. Financial returns have standardised data sources; carbon intensity does not. We built a custom scoring engine that blends company-reported Scope 1 + 2 emissions data, third-party ESG ratings, and fund-level weighted averages — with clear methodology documentation so Illuminate can stand behind the numbers with institutional investors.
The dual-axis chart required careful UX work. Financial return and carbon intensity operate on completely different scales. We normalised both to an index (rebased to 100 at the start of the selected timeframe) so investors can compare the trend of each metric rather than absolute values — which would be meaningless on the same axis.