EMS terminal management
Aug 2020 - Aug 2024· 20 members
Discuss, analyze requirements, and come up with solutions to solve problems.
Java Spring BootZKKafkaActiveMQVernemqEMQX
Software Engineer · Dev Lead · Hanoi
Mai Nhan Phuc
I build sales, fintech & big data systems at enterprise scale.
5+ years building sales, fintech, and big-data systems for Mobifone, Viettel, VNSKY, and Digilife. Now leading technology at Techshield.
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Years
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Projects
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Engineers led
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Domains
01 / About
An engineer who builds systems that last.
Vietnamese / English bilingual. Based in Hanoi. Available for consulting and long-term projects.
I'm Phuc — a software engineer and former dev lead, currently CTO at Techshield from March 2026. Before that, nearly six years at VISSOFT (2020–Feb 2026): started as a team lead at Viettel building EMS terminal management, then expanded through fintech (Epay), affiliate marketing (GREEN EARTH), centralized sales (Digilife BCSS), mobile apps (Sky Sale, ESim), and wrapped up with national-scale credit big data at CIC.
"Code gets rewritten. What stays is a clear architecture, a team that trusts each other, and a process where a new hire stands on their own in two weeks."
Short-term: Strengthen team management and communication skills to deliver projects more efficiently. Mentor junior developers and help team members grow professionally. Optimize workflows and improve code quality within the team.
Long-term: Advance to a senior management role such as Engineering Manager or CTO, leading larger teams and shaping company technology strategy. Become a key contributor in setting technical direction and building an innovative, sustainable engineering culture.
02 / Experience
10 products. 8 years. One thread: systems built for Vietnamese users.
From leading a team of 6 to running a 26-engineer big-data team at VISSOFT (2020–Feb 2026). From Mar 2026, CTO at Techshield.
Period
Company · Role
Highlights
Team
Aug 2020 - Aug 2024
Viettel High Technology Corporation
Team lead · EMS terminal management
Discuss, analyze requirements, and come up with solutions to solve problems.
20 members
June 2021 - Dec 2021
VN GREEN EARTH., JSC
Developer · Affliate Marketing (2021)
Coding.
10 members
Feb 2023 - May 2023
VN GREEN EARTH., JSC
Dev Lead · Affliate Marketing (2023)
Customer exchange.
6 members
Aug 2023 - Dec 2023
EPAY SERVICES JOINT STOCK COMPANY
Dev Lead · Integrate bank payments into Epay e-wallet
Customer exchange.
8 members
Aug 2024 - Mar 2025
Digilife Vietnam Digital Services Co., Ltd.
Dev Lead · Centralized Sales System BCSS
BCSS is a centralized management system for VNSKY telecom, supporting product, sales, and customer management. The platform also includes a partner web portal for SIM stock management and subscriber activation. The system is operated on a modern infrastructure with Kubernetes, Kong Gateway, and monitoring via Kibana.
12 members
Feb 2025 - Jun 2025
Digilife Vietnam Digital Services Co., Ltd.
Dev Lead · Sky Sale App (Part of BCSS Ecosystem)
Sky Sale is an app within the BCSS ecosystem, serving partners to manage SIM inventory, packages, quickly activate subscribers, and synchronize status with VNSKY's central system. The app is developed with Flutter and connects to the BCSS backend.
8 members
Feb 2025 - Aug 20, 2025
Digilife Vietnam Digital Services Co., Ltd.
Dev Lead · Outboard SIM Sales Website
This outboard SIM sales website enables customers to easily purchase SIM cards for international travel, with SEO optimization, great mobile experience, complete order and product management, reconciliation reporting, and ongoing operational support.
8 members
Mar 2025 - Present
GREEN EARTH Vietnam IT & Communication JSC
Deployment & Operation · GEM Web Sale
GEM Web Sale is a system supporting Mobifone's sales operations, managing SIM inventory, numbers, orders, reconciliation reports, multi-channel sales integration, and direct connection to Mobifone and major e-commerce platforms.
5 members
Jun 2025 - Nov 2025
Digilife Vietnam Digital Services Co., Ltd.
Dev Lead · ESim Sales App (Cho ESim)
Cho ESim is an independent app for selling eSIMs and related services to VNSKY and Mobifone, including features like topup. The solution includes a mobile app, a CMS for order and product management, sales reports, and deep integration with the BCSS and GEM ecosystem.
6 members
Nov 2025 - Feb 2026
Vietnam National Credit Information Center (CIC)
Team Lead · National Credit Information Center (CIC)
CIC is a large-scale project related to national credit data, processing and managing credit information from financial institutions. The system uses Apache Cassandra for big data processing, Oracle Database for relational data storage, ELK Stack for monitoring and log analysis, and NextJS for modern web interface.
26 members
03 / Projects
Featured Case Studies
Some notable projects with roles as Developer, Dev Lead, Team Lead
Affliate Marketing (2021)
June 2021 - Dec 2021· 10 members
Coding.
Java Spring BootMicroserviceMariaDBRedisAngular
Affliate Marketing (2023)
Feb 2023 - May 2023· 6 members
Customer exchange.
Java Spring BootMicroserviceMariaDBRedisKafkaAngular
Integrate bank payments into Epay e-wallet
Aug 2023 - Dec 2023· 8 members
Customer exchange.
Java Spring BootMicroserviceOracle Database 19c
Centralized Sales System BCSS
Aug 2024 - Mar 2025· 12 members
BCSS is a centralized management system for VNSKY telecom, supporting product, sales, and customer management. The platform also includes a partner web portal for SIM stock management and subscriber activation. The system is operated on a modern infrastructure with Kubernetes, Kong Gateway, and monitoring via Kibana.
Java Spring BootReactJSOracle DatabaseKubernetes (K8s)Kong API GatewayKibana
Sky Sale App (Part of BCSS Ecosystem)
Feb 2025 - Jun 2025· 8 members
Sky Sale is an app within the BCSS ecosystem, serving partners to manage SIM inventory, packages, quickly activate subscribers, and synchronize status with VNSKY's central system. The app is developed with Flutter and connects to the BCSS backend.
FlutterJava Spring Boot (BCSS backend)Oracle DatabaseKubernetes (K8s)Kong API GatewayKibana
04 / Skills
The stack I actually use — not buzzwords.
Red dot = production-grade across 2+ projects.
Backend
6JavaSpring BootMicroservicesREST / gRPCZK FrameworkNode.js
Frontend & Mobile
5ReactJSNextJSFlutterAngularTypeScript
Database
6Oracle 19cMySQLMariaDBCassandraClickHousePostgreSQL
Infra & DevOps
6KubernetesKong GatewayJenkinsArgo CDDockerGitLab CI
Streaming & Cache
5KafkaRedisActiveMQVerneMQ / EMQXMinIO
Search & Observability
4ElasticsearchKibanaPrometheusGrafana
Leadership & process
7Solution AnalysisDatabaseCodingTechnical Solution DesignBusiness Analysis with BA TeamPost-Go-Live Operational SupportEnglish
05 / Education
Always studying, always upgrading the credential.
May 2023 - Present
Posts and Telecommunications Institute of TechnologyInformation Technology
StudyingApr 2020 - Dec 2022
Vietnam Vocational College of Technology - Handicraft (VCTH)Information Technology (Computer Network Administration)
GraduatedSep 2018 - Apr 2020
Bachkhoa-AptechProgrammer
Graduated06 / Writing
Blog & Knowledge Base
Sharing knowledge about Java Spring Boot, Microservices, system architecture, best practices and real-world experience from projects.
Optimizing Microservice System with Java Spring Boot
Sharing real-world experience on optimizing microservice performance, handling database, message queue, caching and monitoring issues.
January 15, 2025
Migrating from Monolith to Microservices with Spring Boot: Best Practices
Real-world experience on migrating from monolith architecture to microservices, challenges and solutions.
January 10, 2025
Java Spring Boot Best Practices 2025: Code Quality and Performance
Latest best practices for Java Spring Boot development, from code structure to performance tuning.
January 5, 2025
07 / Contact
I'm taking on new projects from Q1 2026.
Email me a short brief: domain, team size, deadline. I usually reply within one business day.
Fastest way to reach me
Email is the main channel. Phone for urgent things.
Open to work
What I'm great at
Dev lead / architect on:
- Centralized sales platforms, multi-channel ERP.
- Banking integration, fintech, e-wallets.
- Big-data pipelines, ETL, observability.
- Monolith splitting / architecture migration.
- Mentoring & onboarding new engineering teams.