Aggregator API Developer Needed

I'm in need of an experienced API developer(s) to assist with integrating our platform with multiple external systems in USA. Plaid API aggregates with multiple finance systems (banks mainly) and their investment aggregation didn't work for me. Since Plaid API didn't work for me I am thinking we will have our own APIs to integrate to any investment banks/ brokers like E*Trade, TD Ameritrade (now part of Schwab(, Vanguard, Fidelity, Robinhood and many more. See

https://plaid.com/products/investments/

Following APIs are needed at high level:
https://plaid.com/docs/api/products/investments/ - Minimum

1) Get Holdings/ Positions (stocks, bonds, mutual funds, options, ETFs, etc.). We will pass institute name, account # or login/password,
2) Get Transactions (Dividend Paid, Bough, Interest Charged, Fees, Sold, Bought positions etc.) for a given account/ institute.

We will publish two things:
1) In order to work with us as a broker/ investment what we need at minimum - certification steps
2) APIs for anyone to work with that broker through our APIs

Key Responsibilities:
- Developing APIs for integrating our system with more than 6 external platforms
- Ensuring smooth and seamless data flow

Ideal candidates should have:
- Proven experience in developing APIs
- A good understanding of data integration
- Experience working with financial systems/ brokerages to understand various investment vehicles one can get
- Different type of accounts / knowledge/ what is IRA or non-IRA for example.

Please message me with your relevant experience and how you can add value to our project.