2016–2018
Technologies of Software Products
Master in Exact Science · Moldova State University
2013–2016
Applied Computer Science
Licentiate in Exact Science · Moldova State University
Vladimir Rodin
Senior Back-end Engineer
Open to new opportunitiesChisinau, Moldova · GMT+3
About
Back-end engineer with 10+ years of experience building and scaling backend systems. I specialize in PHP/Symfony ecosystems, distributed architecture, and performance engineering.
Driven by honest collaboration, technically challenging projects, and the pursuit of elegant solutions. Currently exploring AI-augmented engineering patterns.
Experience
Senior Software Developer · Full-time · Hybrid/Remote
- —Designed and implemented robust system architectures that significantly enhanced application performance and scalability, ensuring they could handle high traffic loads and complex data processing requirements.
- —Led investigation of production errors, diagnosing issues through detailed analysis and debugging, identifying root causes and providing technical summaries to facilitate rapid resolution and prevent recurrence.
- —Led performance tuning initiatives: optimized database schemas, queries, caching strategies, and server configurations, resulting in significant improvements in application speed and resource utilization.
The Brainiac 2023High Flyer 2022
Full-Stack Developer · Full-time · Office
- —Developed and maintained full-stack applications using Symfony/Laravel and Vue.js, ensuring seamless integration and efficient performance across both back-end and front-end.
- —Supported and maintained the integration of IXP Manager, configuring and extending the platform to meet specific requirements and improve overall network management.
- —Integrated with WHMCS for automated billing, client management, and support in web hosting environments, customizing functionalities to align with business requirements.
Web Software Developer · Part-time · Remote
- —Developed and maintained .NET applications, focusing on enhancing functionality, fixing bugs, and optimizing performance across the application lifecycle.
- —Integrated Facebook SDK to enable social media functionalities such as authentication and sharing, managing configuration and ensuring smooth interaction with Facebook services.
- —Led debugging and troubleshooting efforts using logs and debugging tools to identify root causes and implement fixes.
Junior Frontend Developer · Part-time · Office
- —Contributed to the development of an enterprise application using Oracle ADF, implementing user interfaces and integrating them with back-end services.
- —Implemented UI/UX designs based on provided specifications, focusing on responsive and intuitive layouts that enhanced user interaction and usability.
- —Optimized front-end code for performance and maintainability, improving page load times and ensuring smooth interactions across devices and browsers.
Junior Frontend Developer · Part-time · Office
- —Identified and resolved bugs and issues related to front-end functionality in WordPress sites using debugging tools and thorough testing.
- —Enhanced user experience by improving site navigation, layout, and interactive elements, creating intuitive interfaces that supported effective content presentation.
Stack
BackendPHP 8.x · Symfony · Laravel · Node.js
DatabasesMySQL · PostgreSQL · Redis
InfraDocker · CI/CD · Linux · Deploy Automation
FrontendVue.js · TypeScript · HTML/CSS
AI & ToolsGitHub Copilot · Claude · LLM Integration
PracticesSystem Architecture · Code Review · Mentorship · TDD
Cases
ProblemA multi-operator payment platform processed transactions across third-party processors operating in different timezones. All datetime logic was timezone-unaware: reports misaligned across regions, billing period boundaries were incorrect, and scheduled jobs ran at wrong times. Scaling to new operators was blocked.
SolutionLed the full architecture spike and implementation. Designed a system-wide UTC-first strategy: all datetimes stored in UTC, operator timezone resolved at runtime from configuration per deployment. Introduced processor-level timezone configuration in the database. Rebuilt billing period generation to shift boundaries correctly per timezone. Reconfigured all scheduled jobs with explicit timezone settings. Standardised external API and webhook timestamps to ISO 8601. Defined validation rules for allowed timezone identifiers.
ResultDelivered consistent, timezone-correct datetime handling across the entire platform — billing periods, end-of-day flows, processor report ingestion, and external API responses all aligned to operator and processor timezones. Enabled safe onboarding of new processors across multiple continents without datetime regressions.
PHP 8.xSymfonyArchitectureMulti-timezoneDoctrineCron
ProblemCore payment tables used UUID strings as primary keys across a heavily-loaded schema with 18+ dependent tables and complex foreign key graphs. UUID-based PKs caused significant B-tree fragmentation on inserts, bloated indexes due to 36-byte string keys, and degraded JOIN performance across the entire payment, settlement, and refund subsystems. The schema had grown organically — self-referencing tables, cascading constraints, and composite unique indexes made a straightforward migration impossible.
SolutionLed the architecture spike and full implementation. Mapped all 18+ foreign key relationships across payment, settlement, chargeback, audit, and third-party processor tables. Designed a zero-downtime-compatible migration plan: add nullable BIGINT id columns, backfill via incremental UPDATE, drop all dependent foreign keys and unique indexes in correct dependency order, promote BIGINT to AUTO_INCREMENT primary key, backfill integer FK columns in all referencing tables via JOIN, restore all constraints and indexes with Doctrine-generated names. Handled self-referencing parent_uuid separately. Coordinated with the team to ensure all Doctrine entities, repositories, and findBy usages were updated to use integer identifiers.
ResultSignificantly reduced index size on the hottest tables — integer PKs are up to 4x smaller than UUID strings, leading to better buffer pool utilisation and faster index scans. INSERT performance improved due to sequential key allocation eliminating B-tree page splits. JOIN-heavy queries across payment, settlement, and audit tables became measurably faster. Migration deployed as a single coordinated release with no data loss and full constraint integrity restored.
MySQLDoctrinePHP 8.xSymfonyDatabase MigrationPerformanceArchitecture
ProblemAll internal payments — between merchant, referrer, clearing, and settlement accounts — were processed through a third-party banking provider via HTTP. Every internal transfer triggered an external API call, regardless of whether money actually needed to leave the system. With thousands of payments processed daily, this created unnecessary latency, external dependency risk, and tight coupling between business logic and the banking provider throughout the codebase.
SolutionOwned the full architecture spike and implementation plan. Designed a dual-payment-service model: introduced VirtualPaymentService for internal transfers and PhysicalPaymentService for external ones, both implementing a shared interface. Created PaymentServiceFactory to select the correct service based on payment type at runtime. Added isVirtual flag to the Payment entity with a backfill migration. Refactored PaymentProcessor to accept structured arguments instead of callbacks. Decoupled third-party banking credentials into a dedicated SystemAccount entity with per-account-type configuration, and extracted credential resolution into a separate service injected into the payment executor. Redesigned inbound webhook processing to rely on account number and sort code lookups instead of provider-specific internal identifiers. Defined clear parallelisation boundaries so multiple engineers could work on independent streams simultaneously.
ResultThousands of internal payments per day are now processed as virtual transactions — no external HTTP calls, no third-party latency, no unnecessary provider dependency. External banking calls are made only when money actually leaves the system during settlement. The payment engine became significantly more reliable, faster, and easier to reason about.
PHP 8.xSymfonyArchitecturePaymentsDoctrineSystem Design
ProblemA large production codebase was running on PHP 7.4 and Symfony 5.3 — both approaching end-of-life. The team needed to understand the realistic cost and risk of upgrading to Symfony 6.2 and PHP 8.2, including whether to stop at 5.4 or commit to the full major version jump. No upgrade path had been mapped, no deprecations had been tracked, and the work was too large and risky to approach without a structured plan.
SolutionOwned the full spike, planning, and implementation end-to-end. Performed the upgrade locally across dedicated branches, merging the latest production state to validate real-world compatibility. Analysed Symfony changelogs (5.3 → 5.4 → 6.0 → 6.1 → 6.2) and PHP 8.2 backward incompatibility notes in full. Cross-referenced findings with the existing codebase to identify all breaking changes, required deprecation fixes, Docker and PHP INI configuration updates, and PHP 8.2 incompatibilities. Consolidated results from two parallel spikes (PHP 8.2 and Symfony upgrade) into a single coherent execution plan. Used PHP Rector to automate codebase refactoring for PHP 8.2 compatibility and deprecation cleanup, significantly reducing manual effort. Decomposed and created all tickets and subtasks in the upgrade epic with full technical descriptions, documentation links, and story point estimates. Personally executed all 8 upgrade steps in the defined sequence.
ResultDelivered the full upgrade from PHP 7.4 and Symfony 5.3 to PHP 8.2 and Symfony 6.2 — spike, planning, automated refactoring, and implementation all owned by one engineer. The phased approach (5.3 → 5.4 → deprecation cleanup → PHP 8.2 → 6.0 → 6.1 → 6.2) completed with no unplanned regressions.
PHP 8.2Symfony 6.2RectorTech LeadershipDevOpsPlanning
ProblemPayment processing workers were producing daily MySQL deadlocks (1213) and lock wait timeouts (1205) across multiple concurrent payment flows. Over 1900 errors were recorded in an 18-day window. Concurrent workers were locking shared financial entities in inconsistent order depending on which worker ran first. Automatic retries prevented data loss but added latency, increased log noise, and the root cause persisted every day. No defined locking order existed in the codebase.
SolutionOwned the full spike and produced a complete technical proposal. Analysed all deadlock sources, classified error counts by origin, and explained the distinction between deadlock cycles (1213) and lock wait timeouts (1205) sharing the same root cause. Designed a global lock ordering strategy based on the entity dependency graph, with strict ascending id ordering within each entity type to prevent cycles. Designed a pre-transaction lock registry and a single centralised lock acquisition service, leveraging the ORM identity map to eliminate redundant pessimistic lock queries inside transactions. Defined two locking patterns: single-transaction for internal flows and per-callback lock contexts for flows involving external HTTP calls. Improved the retry mechanism: fixed rollback ordering, replaced fixed random delay with exponential backoff with jitter to prevent retry storms. Produced a phased rollout plan with risk levels, incremental migration strategy, and a working POC branch.
ResultDelivered a fully actionable spike with architecture design, root cause analysis, implementation plan, rollout strategy, and POC. Established centralised locking primitives as the canonical approach for the codebase. Defined an incremental migration path that allows per-flow adoption without breaking existing callers, with deadlock elimination as the long-term outcome.
MySQLPHP 8.xSymfonyConcurrencyArchitectureDoctrine
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Jan 2024
The Brainiac 2023 Award · Insight AI (Amdaris)
Award celebrates individuals who have demonstrated exceptional intellectual prowess and innovative thinking in their field. Recipients have showcased their ability to solve complex problems, develop cutting-edge solutions, and contribute significantly to the advancement of their organization.
Jan 2023
High Flyer 2022 Award · Insight AI (Amdaris)
Award is given to employees who demonstrate outstanding performance, dedication, and a commitment to excellence in their roles. This accolade recognizes individuals who quickly adapt and contribute significantly to the company’s success, setting a high standard for others to follow.