Backend engineer building
scalable distributed systems

SmartMail Drive Sync Engine

Scans Gmail for attachments and syncs to Google Drive — zero duplication, crash-safe.

• Gmail API & Drive API with OAuth2 secure auth
• FastAPI + APScheduler fault-tolerant pipeline
• Persistent state via MySQL — restart-safe, no duplicates
• API rate limit handling & long-running stability

Most Java memory tools show you a diagram. I found that most of them — including textbooks — quietly teach wrong mental models. So I diagnosed 8 specific misconceptions, then built a visualizer that corrects each one through how it renders, not through a tooltip or a footnote.

• Each structure rendered to reflect true memory behavior — ArrayList as contiguous cells, LinkedList as scattered individual node objects, Stack as a LIFO tower
• HashMap displays entries by hash bucket index with an explicit "order not guaranteed" warning
• Two-phase GC — objects become GC-eligible first, collected after a random delay, reflecting non-deterministic collection
• Visualizes Stack, Heap & String Pool in real time with animated reference arrows
• Supports 8+ data structures with live Add / Remove controls — no re-run required
• Canvas-rendered BST with dynamic layout and in-order traversal display
• Simulates String interning & Integer cache — including the == trap above 127
• Zero-dependency, single-file — runs in any browser

Most people learn SQL by memorizing syntax. I found the real problem runs deeper — learners have no mental model of what the database is actually doing when a query runs. So I built a visualizer that animates every operation: rows being scanned, filtered, joined, grouped, and mutated — live, step by step, in the order MySQL actually executes them.

• Schema canvas renders CREATE TABLE statements as draggable cards with animated dashed FK arrows connecting foreign key → primary key columns in real time
• JOIN animator scans rows one-by-one with a glowing beam between tables — INNER, LEFT, RIGHT, and FULL JOIN each produce visually distinct Venn diagrams and result streams
• WHERE clause engine supports LIKE, IN, BETWEEN, IS NULL, IS NOT NULL — matching rows flash green, filtered rows get a strikethrough animation before removal
• DML operations — INSERT rows appear with a green flash, UPDATE highlights matched rows in yellow with values applied live, DELETE strikes through then removes, TRUNCATE shows an instant wipe with a side-by-side comparison card explaining the difference
• GROUP BY + aggregates — SUM, AVG, COUNT, MIN, MAX animate as proportional bar charts per group, with NULL exclusion warnings on affected groups
• Execution order explainer — side-by-side view of how you write SQL vs the order MySQL actually executes it, with live step highlighting during every query run
• ORDER BY, LIMIT, and OFFSET animate result slicing with stats card showing total / filtered / returned counts
• Zero-dependency, single-file — runs in any browser with no build step

Personal cloud-based image hosting platform built for global sharing.

• Built using S3 + CloudFront for global image distribution
• Implemented idempotent uploads via deterministic object keys
• Used S3 event triggers for automatic indexing
• Designed lazy-loaded infinite scroll with layout stabilization
• Enforced secure access via IAM roles & bucket policies