Jianping Song`

Need a backend engineer who can make your trading or fintech product stable under real load? I help startups and product teams ship and scale backend systems in Go and Python, especially for exchanges, wallets, and real-time data platforms.

What I have delivered

• Matching engines at 10,000+ TPS with P99 under 5ms - Real-time WebSocket infrastructure for 50,000+ concurrent connections - Clearing, settlement, and account systems with idempotency and reconciliation controls - Multi-chain data processing pipelines handling 1M+ records per day - Production DevOps with Docker/Kubernetes and 99.9% availability Typical engagements:
• Architecture review and rescue for unstable systems - New backend module delivery (API, order flow, risk checks, settlement) - Performance tuning and bottleneck diagnosis - CI/CD, observability, and incident hardening You will get clear communication, milestone-based delivery, and production-focused engineering. If you share your current bottleneck, I can propose an execution plan quickly.

Time zone and collaboration: UTC+8 (Shanghai). I can provide daily overlap windows for UTC and cross-timezone teams.

Freelance / Remote Technical Consultant 2024.01 - Present

Senior Blockchain & Trading System Engineer / Technical Consultant

Provided trading system architecture consulting and core module development services for multiple DeFi and digital asset projects.

Key Contributions

Participated in the architecture design and development of DEX trading systems, responsible for hybrid on-

chain/off-chain architecture design, covering order routing, off-chain matching, and on-chain settlement workflowsContributed to the core system development of a prediction market platform, supporting 5 market types including crypto price prediction with Banker/Normal dual-mode liquidity mechanisms; designed an automated adjudication system based on external data source plugins and a multi-stage settlement engine encompassing 8 strategies; implemented WebSocket real-time market data broadcasting and bot market-

making solutionsDeveloped AI Agent automated trading strategy tools, integrating on-chain data collection, signal analysis,

and automated execution modulesParticipated in Solana program development (Anchor framework), implementing on-chain transaction logic and state managementConducted smart contract code reviews and security assessments for multiple projects, focusing on risks including reentrancy attacks, access control, and Oracle manipulationParticipated in the design and development of an AI multi-agent orchestration system, building a multi-

stage serial/concurrent workflow engine based on TypeScript, integrating MCP protocol, JSON-RPC IPC communication, and LLM circuit-breaking mechanisms; concurrently developed an AI Agent-driven frontend automated refactoring tool, achieving pixel-level visual regression validation through MCP integration with Chrome DevTools

Digital Currency Exchange Platform

Technical Lead

Led the overall technical strategy and team management (8 members) for the company's core trading platform, guiding the team through the complete technical build-out from inception to production launch.

Responsibilities

Managed the backend engineering team, participated in recruitment, task allocation, and performance reviewsLed technology stack selection (Go, Python, React) and system architecture design, decomposing the platform into multiple independent servicesEstablished foundational development standards, including code style conventions, Git workflows, and code review processes

Key Achievements:Matching & Trading System:Designed and implemented a high-performance matching engine; the order book utilized a red-black tree +

doubly linked list structure, with buy/sell orders sorted by price, FIFO at same price level, O(logN) insertion,

O(1)~O(M) matching

Pure in-memory matching with asynchronous persistence: trade results written to MySQL asynchronously via Kafka, with WAL (Write-Ahead Log) ensuring crash recoverySingle-thread-per-trading-pair design: each trading pair processed by an independent goroutine,

eliminating lock contention; multi-pair parallelism enabling linear throughput scalingPerformance optimization: object pool reuse of order structures to reduce GC pressure, batch processing

(10ms/100 orders), zero memory allocation on critical pathsBenchmark results: load testing with wrk + custom Lua scripts, achieving peak 10,000+ TPS, P99 < 5ms,

CPU < 70%

Clearing & Settlement System:Designed a complete settlement pipeline: matching → fund freezing → debit/credit → unfreezing, with end-to-end transaction guaranteesAdopted local message table + eventual consistency pattern for cross-service distributed transactions,

with asynchronous Kafka messaging and scheduled compensation scanning for timed-out messagesIdempotency handling: unique business ID constraints to prevent duplicate settlements; optimistic locking

(version field) on account changes to prevent concurrency conflictsDaily automated reconciliation: account balances vs. transaction flow summary auto-comparison, with real-time alerts on discrepancies

Account & Asset System:Designed the account model (available balance + frozen amount + optimistic lock version), supporting core functions including deposits, withdrawals, and asset freezingDeposit deduplication using on-chain txHash as unique key; withdrawal flow controlled by state machine

(Pending → Broadcasting → Confirmed)Complete fund flow records supporting audit trails by business type and business ID

Market Data & Real-time Broadcasting:Built a WebSocket gateway cluster (3 nodes, 20,000+ connections per node), supporting 50,000+

concurrent connectionsMarket data distributed across nodes via Redis Pub/Sub, with gateway-side batched broadcasting grouped by trading pair channelsMessage compression: gzip compression for JSON dataHeartbeat detection + exponential backoff reconnection, with automatic resubscription on disconnection

Risk Control & Compliance:Built a real-time risk control engine: trade limit management, anomalous behavior monitoring, suspicious transaction reportingAccess layer rate limiting: max 10 connections per IP, max 5 connections per user, message rate of 100

messages/secondEstablished KYC/AML workflows, integrated with third-party identity verification services

Tech Stack: Go (Gin), Python (FastAPI), React + TypeScript, MySQL, PostgreSQL, Redis, Kafka, Docker,

Kubernetes, Prometheus + Grafana

Blockchain Technology Company

Backend Developer → Senior Backend Developer

Responsible for backend development of the company's multi-chain digital asset wallet and related backend systems; later promoted to Senior Engineer serving as a technical backbone.

Key Contributions

Participated in product requirement discussions and technical solution design, responsible for technical coordination with frontend teams (Web / Mobile / Mini Programs)Designed unified API specifications and error code standards, improving team collaboration efficiencyLed backend service architecture optimization, covering user accounts, asset management, and notification modules

Key Achievements:Multi-chain Wallet & Asset Management System: Designed account models for multi-asset, multi-

account scenarios, supporting asset management, deposits/withdrawals, and balance synchronization across 10+ blockchains (BTC, ETH, TRON, EOS, etc.)

On-chain Data Processing: Implemented block scanning, transaction parsing, and event listening services, processing 1M+ on-chain data records daily, ensuring timeliness and accuracy of deposit/withdrawal confirmations

Performance Optimization: Identified bottlenecks through distributed tracing (Jaeger); applied comprehensive optimizations including index optimization (full table scan → index hits), N+1 query elimination (loop queries → JOIN batch queries), Redis hot cache (5min TTL + random offset to prevent cache stampede), and connection pool tuning (10 → 50 connections + warm-up), reducing core API response time from 500ms to 50ms

Tech Stack: Node.js (Express), Python, Go, React Native, Vue.js, MySQL, MongoDB, Redis

Private Equity Fund Management Company

Backend Development Intern

Interned at the company's technology department during undergraduate studies, participating in the development of backend systems related to quantitative trading and financial data.

Key Contributions

Participated in the development of the quantitative strategy management dashboard, responsible for API implementation of modules including strategy configuration, backtesting data display, and trade record queriesParticipated in financial data table schema design and query optimization, developed market data statistics and strategy performance analysis logicCollaborated with frontend teams on integration testing and debugging

Tech Stack: PHP (Laravel), MySQL, Red

Henan University of Economics and Law | Network Engineering (Bachelor's)