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Yao David Logan

Software Engineer fullstack specialized in SaaS, business automation and scalable web/mobile platforms.

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SaaS energy consumption simulator: savings, CO₂, and real-time action plan.

Fullstack Engineer2026Up to 70% savings on heating, -75% CO₂
Context2026

SaaS energy consumption simulator: savings, CO₂, and real-time action plan.

SaaS simulator that computes household or building energy consumption in real time and proposes a quantified action plan (heating savings, CO₂ reduction, payback period). The tool targets homeowners and energy consultants who need a clear diagnostic to decide on renovations. Modeling is parameterizable by housing type, insulation level, heating mode and climate zone. Results are explained in plain language, not thermal jargon.

Scope
Fullstack Engineer · Fullstack
Stack
Next.js · Node.js · TypeScript
Signal
Up to 70% savings on heating, -75% CO₂
ChallengeBefore intervention

Blocked identified.

Consumer-grade energy simulators give opaque figures or demand endless forms. Professional advisors juggle spreadsheets and expensive specialized software. No middle-ground solution offered both ease of use, transparent calculations and clear, client-ready output.

Risk addressedFullstack Engineer · Fullstack
ApproachAfter delivery

Answer built.

A Node.js calculation engine based on current thermal regulations, parameterized by climate zone and housing type. Coefficients are externalized in JSON to allow updates without redeployment. The Next.js interface guides the user through short steps (area, insulation, heating, windows) and shows results live: kWh/m²/year, annual cost, potential savings, CO₂ equivalent. An "action plan" prioritizes renovations by ROI.

Foundation deliveredNext.js · Node.js · TypeScript
Results

Measurable impact

Metrics give a quick read of the case study effects.

Heating savings
70%
After70%
CO₂ reduction
75%
After75%
Simulation duration+-85% vs before
90 s
Before600 s
After90 s
EvolutionPost-launch progression
100500
BEFORE100
+INSULATION72
+HEAT PUMP48
+SOLAR30
Architecture

System delivered

A simple read of the functional blocks and their interactions.

clientUI Next.js
gatewayAPI Node.js
serviceCalculation engine
serviceReport service
databasePostgreSQL
externalJSON coefficients
UI Next.jsAPI Node.jsREST
API Node.jsCalculation engineCalculation
Calculation engineJSON coefficientsRead
API Node.jsReport serviceGeneration
Report servicePostgreSQLPersistence
Calculation accuracy90%
Simulation speed92%
Report clarity88%
Measured savings86%
Main signalUp to 70% savings on heating, -75% CO₂

Up to 70% heating savings and 75% CO₂ reduction measured on pilot cases.

Deliverables
  • Calculation engine configurable by climate zone and typology
  • Readable report: kWh, cost, CO₂, ROI of work
  • Action plan prioritized by return on investment
  • Coefficient updates without deployment (JSON config)
Stack
Next.jsNode.jsTypeScriptPostgreSQLRecharts
Public demoDiscuss a similar need
Collaboration

Let's turn a fuzzy need into a shippable product.

Product diagnosis, SaaS architecture, backend, interface and automations that make a platform usable.

Format
Full-time, freelance, long mission
Focus
SaaS, API, back-office, automation
Discuss a projectDownload CV