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Projects/Add Co-funding Info in Projects & Budget Bills
Backend / APILive

Add Co-funding Info in Projects & Budget Bills

Brought co-funding data online across projects and budget bills for precise attribution and cost-sharing transparency across multiple regions.

2026-cofunding-budget-project · main
# E-Commerce / Budget & Finance
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Role
Senior Backend Engineer
Timeline
2026
Team
4
Domain
E-Commerce / Budget & Finance
Stack
8 tech
Status
Live
01

Overview

This project standardizes how co-funding information is recorded in Project Management and Budget Bill systems, replacing manual offline tracking of platform-vs-seller cost splitting. As the lead backend engineer, I drove the technical assessment, requirements document, and backend design for rolling co-funding data out across multiple regions.

A backend has no screens, so its "UI" is the operational surface: the API contract, the ops flow, and the cross-service change map.

API contract — co-funding fields on budget & proposal endpoints
Ops view — co-fund ratios & caps per budget bill
Change map — cross-service interface contract & schema impact
03

Problem & Solution

Problem

Without an online co-funding data model, cost-sharing ratios and caps were tracked manually — low transparency, higher error risk, and weak budget attribution across projects and budget bills. This grew more problematic as co-funding expanded to more regions.

Solution

I designed the backend changes to embed co-funding metadata into core campaign and budget flows: a new co-funding info table, additional columns in existing budget structures, and updates to key APIs and interface contracts used by the proposal, budget, and gateway layers (set-budget, get-proposal, create-bill, list-bills APIs). I led requirement clarification with PM, aligned the design with the earlier budget-foundation work, and prepared it for technical review.

04

Workflow

Three actors interact with the service; the diagrams are written in English to stay consistent across both languages.

flowchart diagram

set source project type

set co-fund ratio & cap

Ops / PM

Project Service

Budget Service

Gateway

Ops Console

Use case interaction
sequence diagram
Budget ServiceProposal ServiceGatewayOps ConsoleBudget ServiceProposal ServiceGatewayOps Consoleset-budget (co-fund info)get-proposalproposal + source project typecreate-bill (co-fund ratio, cap)list-bills (co-fund section)
Sequence flow
05

Architecture

flowchart diagram

metrics

Ops Console

Gateway

Proposal Service · Go

Budget Service · Go

Co-funding Info Table

Budget Tables

Prometheus / Grafana

System architecture
Architecture notes

Co-funding is modeled as first-class metadata: the Budget Service persists ratios, caps, and source-project types in co-funding info table, while the Proposal Service and Gateway carry the new fields through their interface contracts. A mandatory "Source Project Type" on project items and a "Co-fund Info" section on budget bills drive attribution across multiple regions.

state diagram

ratio & cap set

linked to budget bill

draft

configured

attached

active

Co-fund record lifecycle
06

Features

Finance / Operations
  • Mandatory "Source Project Type" on project items
  • Co-fund ratios & caps captured per budget bill
  • Transparent platform vs seller cost splitting
System
  • New co-funding info table
  • Updates to set-budget / get-proposal / create-bill / list-bills APIs
  • Cross-service interface contract changes (Proposal / Budget / Gateway)
  • Multi-region rollout
07

Tech Stack

language
Go
framework
RPCHTTP framework
database
Managed RDS
protocol
RPCHTTP
infra
Multi-region
observability
PrometheusGrafana
08

Engineering Challenges

01
Translating financial co-funding rules into cross-service design

Co-funding logic had to fit existing project, proposal, budget, and gateway flows without fragmenting implementations. Fix: map requirements into shared schema and contract updates across services rather than one-off patches.

02
Multi-region rollout aligned with prior infrastructure

The design had to cover multiple regions and reuse the earlier budget foundation. Fix: align co-fund data modeling with the earlier budget-foundation work for consistency and reuse.

09

Outcomes

14
regions in scope
4
core APIs updated
3
service layers impacted
1
new co-fund table
10

Lessons Learned

Financial data integrations benefit from a simple, shared metadata model early in design. Treating co-funding as a first-class object across services — not a one-off field patch — made the solution clearer, easier to review, and more extensible for future markets.

11

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