This week, we start off our API performance highlights reel with something that’s been stumping us here at the office: Bank of Ireland UK.
Bank of Ireland, which can be found in the Open Banking UK Open Data collection, was in the Red Zone last week with a CASC score of 4.49. What happened?

The low CASC score is due to a massive issue with all of their monitored open data endpoints beginning on the 16th of September. The endpoints returned a range of HTTP 503 Service Unavailable, 502 Bad Gateway, and 404 Not Found responses.
So, what does that mean in the real world?
The client sends a request to the server that isn’t actually the server serving it. It’s a special type of server, knows a load balancer, which sits in front of everything else, so that’s what the clients interact with, and it takes the client request and figures out which back-end server it’s going to send it to.
Normally, if the back-end server was down or unreachable, you’d expect it to be a 503, because that load balancer should be performing health checks on the back end servers and it will register if it’s down.
But the fact that it’s also returning a 502 means it’s talking to it, but they’ve just done something that’s made it return garbage. And the 404s are the real plot twists in here.
When API Performance Affects Customers
One of the endpoints that we saw affected is to locate ATMs. This means that for the last four days, no one has been able to find the closest ATM to them. Now, this isn’t as urgent as, say, not being able to check your balance. But still, it’s a customer-facing API that people are going to notice.
So, let’s say customers have contacted Bank of Ireland about this. If it’s doing these redirects, it may very well be that DevOps at Bank of Ireland is sitting there thinking it’s working.
Which means that when customer service tries to tell DevOps that something isn’t working, DevOps is saying, nope, it’s fine, and it’s back and forth with wasted time and resources until someone finally figures it out.
Meanwhile, customers are inconvenienced, DevOps is panicking, customer service is tap dancing, and it’s a mess.
This is the exact scenario that our CEO, David O’Neill, brings up all the time when trying to explain why APImetrics just makes good business sense.
Moving on.
More API Performance Highlights

SimpleSwap in the Exchanges collection was in the Red Zone with a CASC score of 5.23. This was due to a large cluster of outliers on the 12th combined with a few HTTP 521 Web server is down errors.

Dept of Energy in the US Government collection was in the Red Zone with a CASC score of 3.56. We need to find a thesaurus and look up alternative ways to say how bad the Department of Energy’s API is. Jokes aside, they have got slightly better this week with the outlier rate dropping by 2.62% points to 17.5%. Having said that, they still have far to go.
Honorable Mentions
- NewDay – Amazon Mastercard in the Open Banking UK Production, NewDay – Aqua in the Open Banking UK Production, Allied Irish Bank in the Open Banking UK Open Data category takes the overall title for best API again this week with a CASC score of 9.78.
- Contentful in the GGV Capital API-First category is the fastest API again this week with an average latency of 48 ms, the same as last week.
- Monzo Bank is the best-performing bank in the Open Banking UK Production category with monitored AISP (non-consent) endpoints again this week with a CASC score of 9.21, down from 9.25 last week.
- Dept of Energy in the US Government category is the overall worst performing API again this week with a CASC score of 3.56, up from 3.26 last week.
- 8 categories are topped by an API with a CASC score of 9.50 or more, down from 10 last week.
- 15 categories are topped by an API with a CASC score of 9.00 or more, the same as last week.
- 1 categories have bottom API with a CASC score of 9.00 or more, the same as last week.
- 7 categories have bottom API with a CASC score of 8.00 or more, down from 15 last week.
- 5 APIs (SimpleSwap in the Exchanges collection with a CASC score of 5.23, Cater Allen Private Bank in the Open Banking UK Production collection with a CASC score of 4.02, Tide Platform Ltd in the Open Banking UK Production collection with a CASC score of 5.66, Bank of Ireland in the Open Banking UK Open Data collection with a CASC score of 4.49, Dept of Energy in the US Government collection with a CASC score of 3.56) are in the Red Zone with a CASC score of less than 6.00 this week, up from 4 last week.
Collection | Project | Change |
---|---|---|
Corporate Infrastructure | PagerDuty | -2 |
Enterprise Messaging | Microsoft Graph (Teams) | -1 |
Exchanges | Huobi Global | -4 |
Fintech | Truelayer | -3 |
GGV Capital API-First | Alpaca | -6 |
IP Geolocators | ipgeolocator | -1 |
Open Banking UK Open Data | Bank of Ireland | -6 |
Open Banking UK Production | Bank of Ireland (UK) Plc | -23 |
Open Banking UK Sandboxes | OBIE Sandbox | -2 |
PSD2 Institutions | Deutsche Bank | -1 |
Search | Foursquare | -2 |
UK Government | DEFRA | -1 |
US Government | Dept of Justice | -5 |
Changes
Corporate Infrastructure
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
PagerDuty | 9.03 | 9.13 | 11 | 9 | -2 |
Salesforce | 9.45 | 9.54 | 3 | 2 | -1 |
Pivotal Tracker | 9.5 | 9.45 | 2 | 3 | 1 |
Dropbox | 9.13 | 8.98 | 9 | 11 | 2 |
Corporate Messaging
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|
Enterprise Messaging
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
Microsoft Graph (Teams) | 8.48 | 8.52 | 5 | 4 | -1 |
Cisco | 8.51 | 8.2 | 4 | 5 | 1 |
Exchanges
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
Huobi Global | 8.58 | 8.96 | 23 | 19 | -4 |
Gate.io | 8.91 | 9.01 | 19 | 16 | -3 |
BitMEX | 7.64 | 8.55 | 29 | 26 | -3 |
bitFlyer | 9.05 | 9.19 | 13 | 10 | -3 |
Binance | 8.5 | 8.74 | 25 | 22 | -3 |
LA Token | 9.1 | 9.2 | 11 | 9 | -2 |
OKEx | 9.46 | 9.56 | 4 | 2 | -2 |
Korbit | 8.97 | 9.06 | 16 | 15 | -1 |
CryptoCompare | 8.92 | 9.01 | 18 | 17 | -1 |
Binance US | 9.18 | 9.26 | 9 | 8 | -1 |
Liquid | 8.13 | 8.25 | 28 | 29 | 1 |
Coin Metrics | 9.57 | 9.51 | 3 | 4 | 1 |
Bitfinex | 9.14 | 9.18 | 10 | 11 | 1 |
Bithumb | 8.55 | 8.65 | 24 | 25 | 1 |
Coinbase | 8.93 | 8.98 | 17 | 18 | 1 |
Bitrrex | 9.08 | 9.1 | 12 | 13 | 1 |
Gemini | 9.61 | 9.54 | 2 | 3 | 1 |
Coinpaprika | 8.89 | 8.91 | 20 | 21 | 1 |
3commas | 8.65 | 8.68 | 22 | 23 | 1 |
CoinMarketCap | 8.46 | 8.33 | 26 | 28 | 2 |
HitBTC | 8.72 | 8.67 | 21 | 24 | 3 |
Coinone | 9.19 | 9.16 | 8 | 12 | 4 |
Bitstamp | 9.04 | 8.91 | 15 | 20 | 5 |
Fintech
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
Truelayer | 8.67 | 8.76 | 10 | 7 | -3 |
DNB currency APIs | 9.18 | 9.46 | 6 | 4 | -2 |
Tink | 9.42 | 9.6 | 3 | 2 | -1 |
Stripe (Sandbox) | 9.49 | 9.67 | 2 | 1 | -1 |
Paypal (Sandbox) | 8.87 | 9.04 | 7 | 6 | -1 |
Intuit | 8.51 | 8.52 | 11 | 10 | -1 |
Plaid (Sandbox) | 8.76 | 8.73 | 9 | 8 | -1 |
Finicity | 9.41 | 9.35 | 4 | 5 | 1 |
Yapily | 8.84 | 8.71 | 8 | 9 | 1 |
Wise APIs (Sandbox) | 9.52 | 9.53 | 1 | 3 | 2 |
Square (Sandbox) | 9.35 | 8.43 | 5 | 11 | 6 |
GGV Capital API-First
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
Alpaca | 8.7 | 8.96 | 20 | 14 | -6 |
Unit | 8.84 | 9.06 | 16 | 10 | -6 |
Algolia | 9.07 | 9.35 | 9 | 4 | -5 |
Duffel | 8.8 | 8.96 | 19 | 15 | -4 |
Courier | 8.68 | 8.89 | 21 | 17 | -4 |
Stedi | 7.84 | 8.24 | 30 | 27 | -3 |
EMnify | 8.4 | 8.64 | 26 | 23 | -3 |
Shippo | 9.05 | 9.12 | 11 | 9 | -2 |
Deepgram | 7.92 | 8.43 | 28 | 26 | -2 |
Plaid | 8.47 | 8.56 | 25 | 24 | -1 |
Stripe | 9.41 | 9.64 | 2 | 1 | -1 |
MessageBird | 9.02 | 9.04 | 12 | 11 | -1 |
Gretel | 8.8 | 8.87 | 18 | 19 | 1 |
Contentful | 9.47 | 9.52 | 1 | 2 | 1 |
Persona | 7.84 | 6.8 | 29 | 30 | 1 |
Fidel API | 8.51 | 8.56 | 24 | 25 | 1 |
Railsbank | 8.13 | 8.15 | 27 | 28 | 1 |
Alchemy | 9.05 | 9.04 | 10 | 12 | 2 |
Belvo | 8.83 | 8.86 | 17 | 20 | 3 |
Stytch | 8.95 | 8.88 | 14 | 18 | 4 |
Modern Treasury | 9.24 | 9.16 | 4 | 8 | 4 |
Merge | 8.52 | 7.9 | 23 | 29 | 6 |
Radar | 8.9 | 8.78 | 15 | 21 | 6 |
Lob | 9.08 | 8.94 | 8 | 16 | 8 |
IP Geolocators
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
ipgeolocator | 9.4 | 9.4 | 3 | 2 | -1 |
ipdata | 9.43 | 9.5 | 2 | 1 | -1 |
ipwhois | 9.45 | 9.27 | 1 | 3 | 2 |
Open Banking UK Open Data
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
Bank of Ireland | 4.49 | 9.65 | 9 | 3 | -6 |
Danske Bank | 9.47 | 9.64 | 3 | 4 | 1 |
Nationwide | 9.29 | 9.59 | 4 | 5 | 1 |
Santander | 8.73 | 8.58 | 6 | 7 | 1 |
HSBC | 7.62 | 7.85 | 7 | 8 | 1 |
Barclays | 7.3 | 7.53 | 8 | 9 | 1 |
Lloyds Group | 8.98 | 8.86 | 5 | 6 | 1 |
Open Banking UK Production
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
Bank of Ireland (UK) Plc | 8.58 | 9.73 | 24 | 1 | -23 |
Creation Cards | 8.8 | 9.7 | 20 | 2 | -18 |
Cumberland Building Society | 9.01 | 9.16 | 16 | 12 | -4 |
Danske Bank (Personal) | 9.51 | 9.69 | 6 | 3 | -3 |
TSB | 8.75 | 9.03 | 21 | 18 | -3 |
Ulster Bank NI | 8.96 | 9.11 | 18 | 15 | -3 |
Barclays Business | 8.24 | 8.3 | 26 | 24 | -2 |
Barclays Personal | 8.11 | 8.26 | 27 | 25 | -2 |
Cashplus Bank | 7.82 | 8.08 | 28 | 27 | -1 |
HSBC Bank (Business) | 8.61 | 8.79 | 23 | 22 | -1 |
Sainsbury’s Bank | 9.67 | 9.69 | 5 | 4 | -1 |
OBIE Directory | 8.71 | 8.8 | 22 | 21 | -1 |
NatWest Production | 9.15 | 9.16 | 12 | 11 | -1 |
Halifax | 9.02 | 9.05 | 15 | 16 | 1 |
Allied Irish Bank (GB) | 9.67 | 9.64 | 4 | 5 | 1 |
Tesco Bank | 8.89 | 8.85 | 19 | 20 | 1 |
Vanquis Bank | 8.49 | 8.22 | 25 | 26 | 1 |
HSBC Bank (Personal) | 9.15 | 9.13 | 13 | 14 | 1 |
Lloyds Bank | 8.99 | 8.9 | 17 | 19 | 2 |
Revolut | 9.76 | 9.58 | 3 | 6 | 3 |
Bank of Scotland | 9.09 | 9.03 | 14 | 17 | 3 |
NewDay – Amazon Mastercard | 9.78 | 9.29 | 1 | 8 | 7 |
NewDay – Aqua | 9.78 | 9.14 | 2 | 13 | 11 |
Virgin Money | 9.31 | 8.43 | 8 | 23 | 15 |
Capital One | 9.15 | 7.97 | 11 | 28 | 17 |
Open Banking UK Sandboxes
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
OBIE Sandbox | 8.13 | 8.93 | 6 | 4 | -2 |
Bank of Ireland Sandbox | 8.52 | 9.4 | 4 | 3 | -1 |
Danske Sandbox | 8.4 | 8.52 | 5 | 6 | 1 |
RBS Sandbox | 8.86 | 8.87 | 3 | 5 | 2 |
PSD2 Institutions
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
Deutsche Bank | 8.13 | 8.73 | 3 | 2 | -1 |
ABN | 8.35 | 8.49 | 2 | 3 | 1 |
Search
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
Foursquare | 8.88 | 8.98 | 4 | 2 | -2 |
Bing | 9.07 | 8.67 | 2 | 4 | 2 |
UK Government
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
DEFRA | 8.49 | 8.8 | 3 | 2 | -1 |
Police.UK | 8.76 | 8.77 | 2 | 3 | 1 |
US Government
Project | Current CASC Score | Previous CASC Score | Current Rank | Previous Rank | Change |
---|---|---|---|---|---|
Dept of Justice | 8.33 | 9.31 | 8 | 3 | -5 |
Dept of Commerce | 6.71 | 7.83 | 13 | 9 | -4 |
Bureau of Labor Statistics | 9.31 | 9.41 | 2 | 1 | -1 |
US Census Bureau | 8.04 | 8.15 | 9 | 8 | -1 |
FEMA | 7.72 | 7.35 | 12 | 11 | -1 |
FEC | 9.07 | 8.97 | 4 | 5 | 1 |
Dept of Housing and Urban Development | 9.46 | 9.4 | 1 | 2 | 1 |
Veterans Affairs | 9.15 | 9.1 | 3 | 4 | 1 |
NASA | 7.76 | 6.9 | 11 | 12 | 1 |
Data.gov | 9.0 | 6.64 | 5 | 13 |