Technical Lead · Go Backend Engineer · Open to Freelance
Software engineer with 7+ years of experience building and evolving backend systems across fintech, capital markets, and maritime HRIS.
I focus on backend architecture, complex business workflows, system reliability, performance, security, and engineering leadership.
Currently open to freelance opportunities, especially for backend development, Go engineering, API development, system architecture, performance optimization, and technical consulting.
I'm currently working as a Technical Lead, leading technical direction, architecture, and engineering delivery for a maritime HRIS platform supporting shipping companies and crewing operations.
My work involves translating complex business requirements into reliable systems, designing backend architecture, reviewing technical decisions, mentoring engineers, and collaborating across Product, QA, Frontend, DevOps, Data, Operations, and other stakeholders.
I enjoy solving engineering problems around:
- Backend architecture & system design
- Complex business logic & domain modelling
- High-performance APIs
- Distributed & asynchronous workflows
- Database design & optimization
- Reliability & observability
- Security-conscious backend development
- Production engineering
- Engineering leadership & mentoring
Go · REST API · gRPC · Kafka · WebSocket · Server-Sent Events
PostgreSQL · MySQL · Redis · SQL
Docker · Kubernetes · Linux · Nginx
Datadog · Sentry · Monitoring · Caching · Background Workers
System & Database Design · Backend Architecture · Performance Optimization · Code Review · Technical Leadership
Worked on backend systems covering complex financial workflows such as:
- Payment processing
- Loan repayment
- Loan restructuring
- Credit underwriting
- Payment priority
- Payment tolerance
- Discount management
- Fee structures
- Third-party integrations
- Financial regulatory workflows
I also worked extensively with REST APIs, gRPC, Kafka, scheduled jobs, internal back-office systems, monitoring, and production issue resolution.
Currently working on a specialized maritime HRIS platform covering interconnected operational domains such as:
- Crew management
- Vessel planning
- Crew rotation & movement
- Employment contracts
- Payroll
- Salary structures
- Bonuses & deductions
- Multi-currency calculations
- Payslip generation
- Appraisal
- Audit logging
- Compliance-related workflows
The platform involves complex domain relationships where changes in crew, vessel, contract, payroll, or operational data can affect multiple workflows and stakeholders.
My work includes designing transaction-safe business logic, asynchronous processing, background workers, caching, and real-time frontend updates.
Previously worked on financial-market systems supporting:
- e-IPO
- e-GMS
- e-Voting
- Right Issues
- Issuer platforms
- Investor platforms
- Internal corporate systems
During this period, I migrated backend services from PHP to Go and improved the performance of several systems by approximately 10x–100x.
I also worked on database scaling, server infrastructure, application security, monitoring, and high-availability systems for critical financial activities.
Beyond writing code, my responsibilities include:
- Defining technical direction
- Designing system architecture
- Breaking down complex engineering problems
- Reviewing technical solutions
- Code review
- Establishing engineering standards
- Mentoring engineers
- Delegating engineering tasks
- Technical interviews
- Candidate evaluation
- Engineer onboarding
- Production incident resolution
- Cross-team technical coordination
I work closely with engineering and product stakeholders to balance technical quality, delivery speed, maintainability, and business requirements.
Security has always been an important part of my engineering work.
Alongside backend engineering, I also have experience with:
- Application security
- Secure API development
- Request validation & middleware
- Penetration testing
- Vulnerability validation
- Security assessments
- Responsible disclosure
- Security recommendations
- Production security monitoring
I have also worked independently as a Freelance Penetration Tester, helping identify, validate, document, and responsibly disclose security vulnerabilities.
I prefer building systems that are:
Reliable
Systems should behave predictably under real production workloads.
Maintainable
Architecture and code should be understandable and safe to evolve.
Observable
Problems should be measurable and visible before they become major incidents.
Secure
Security should be considered during system design, not added as an afterthought.
Scalable
Systems should be designed with future growth and operational complexity in mind.
Practical
Good architecture should solve real problems without introducing unnecessary complexity.
I'm currently open to freelance projects and technical collaborations.
Areas where I can help:
- Go / Golang backend development
- Backend system development
- REST API development
- gRPC services
- Backend architecture
- System design
- Database architecture
- PostgreSQL / MySQL optimization
- Backend performance optimization
- Legacy backend modernization
- Code review
- Backend technical assessment
- Technical consulting
- Application security review
- Backend troubleshooting & production issues
For larger or more complex projects, I can also help with technical planning, architecture decisions, engineering standards, and backend team direction.
I'm particularly interested in:
- Go internals
- Distributed systems
- High-performance backend systems
- Database internals & optimization
- Event-driven architecture
- Backend observability
- Application security
- Developer tooling
- Engineering productivity
- System architecture
I'm always interested in discussing backend engineering, Go, system architecture, performance, reliability, security, and challenging engineering problems.
If you have a freelance project, technical collaboration, or backend problem that needs to be solved, feel free to reach out.
LinkedIn
https://www.linkedin.com/in/muhammad-saleh-solahudin-8444171b2
TikTok
https://www.tiktok.com/@msalehsolahudin
Portfolio
https://s.id/web-msalehs