Part of the Sanchayam series. Why Friday Portfolio performance is tracked week by week, not day by day. Daily snapshots would generate a large amount of data for a view that is displayed weekly at best. Friday is chosen because Indian markets close at 3:30 PM IST on Friday. The snapshot cron runs at 11:00 AM UTC, which is 4:30 PM IST - 30 minutes after market close, giving price feeds time to settle. ...
Part of the Sanchayam series. Why FIFO FIFO (first in, first out) is the standard cost basis method for Indian equities and mutual funds for tax purposes. When you sell shares, the oldest lots you bought are assumed to be the ones sold first. The cost basis of those oldest lots determines your taxable gain. Sanchayam implements FIFO at sell time: when a sell lot is recorded, the backend walks the buy lots in chronological order, consuming them until the sell quantity is satisfied, and computes the aggregate cost. ...
Part of the Sanchayam series. Why a Queue A price fetch is an external API call. It can be slow, it can fail, it needs rate limiting, and it should not block a user request. The right place for it is a background worker draining a persistent queue, not an inline synchronous call. When the frontend requests holdings data and a price is missing or stale, the backend responds immediately with what it has and enqueues the asset for a fetch. The next time the user loads the page, the price is ready. There is no blocking wait. ...
Part of the Sanchayam series. Why FX Matters Sanchayam tracks assets in their native currency. An Indian equity is priced in INR. A US stock is priced in USD. Crypto may be in USD or USDT. A bank account might be in AED. The portfolio view needs to aggregate everything into one base currency (the user’s choice - INR by default). Every portfolio snapshot, every holdings page, every P&L calculation requires converting across currencies. FX rates are fetched from the same Twelve Data API used for price feeds. A naive approach - one API call per currency per request - would be both slow and expensive. ...
Part of the Sanchayam series. The Problem with Per-Type Tables The obvious design for a multi-asset tracker is a table per asset type: one for stocks, one for mutual funds, one for real estate. That approach breaks down when you need cross-asset aggregation. Computing total portfolio value means querying five different tables and unioning them. Adding a new asset type means new tables, new routes, new UI components. Sanchayam uses a single assets catalog and a single holdings table. Behavior differences between asset types are encoded in schema flags, not in separate tables. ...