Residential Construction Operations & Pricing Platform

A major German residential construction and turnkey home builder needed a centralized operations platform to manage the end-to-end lifecycle of solid-construction residential projects. Project managers and site supervisors (Bauleiter) needed to track construction progress across multi-phase milestones, manage element and house configuration pricing, and automate site reporting.

• Architected the Konfigurator pricing engine: designed and locked in an immutable historical price-layer / ledger model that tracks element additions, removals, formulas, and custom discounts without corrupting historical contract values.
• Shipped the Projektverlauf-Admin ("Project History Admin") module end-to-end, delivering the complete PR package: Retool application, database schema updates, and technical Confluence documentation.
• Co-designed the v2 relational database schema diagram and refactored core milestone join logic from address records to person entities, improving relational consistency across dependent modules.
• Implemented secure file and photo upload pipelines to AWS S3 with automated malware scanning, verifying security enforcement using EICAR test payloads.
• Built Bauleiter site management reports and queries directly for executive stakeholders.
• Ran recurring daily standups and extensive requirement discovery / design review sessions with client stakeholders across the 2+ year engagement.

• Append-Only Pricing Ledger vs. Mutable State: In construction sales, house element configurations frequently change over months of planning. Recalculating totals on the fly against active master price lists risks altering signed contracts. Implemented an append-only pricing ledger where changes append compensating credit/debit adjustment layers, preserving full auditability.
• Entity Join Refactoring: Addressed fragile milestone queries by decoupling construction milestones from physical site addresses and anchoring them directly to person entities, eliminating data fragmentation when contacts or parcels were updated.

Shipped and maintained the core Retool operational suite across construction milestone tracking, site reporting, and pricing configuration. At project conclusion, received direct commendation from client leadership as the best external contractor they had engaged, specifically noting high autonomy and zero need for ramp-up training.